1. Field of the Invention
The present invention generally relates to an electronic device, and more particularly, to an electronic device having spiral-shaped coils longitudinally spaced from each other.
2. Description of the Related Art
An inductor or a capacitor is used for phase matching or the like. For example, there is a demand for downsizing, low cost and high performance in a RF system such as mobile phone or wireless LAN (Local Area Network). An electronic device such as an integrated passive device where passive devices such as an inductor or a capacitor are integrated on a substrate is used in order to satisfy the demand.
Japanese Patent Application Publication No. 2006-157738 discloses an integrated electronic device using a spiral-shaped coil on a substrate acting as an inductor. Japanese Patent Application Publication No. 2007-67236 and U.S. Pat. No. 6,518,165 disclose an inductor in which spiral-shaped coils are longitudinally spaced from each other.
In accordance with the inductor disclosed in Japanese Patent Application Publication No. 2007-67236, high Q value is obtained. There is, however, a problem that mechanical strength and impact resistance of an upper layer coil are not sufficient, because the coils are longitudinally spaced from each other in the inductor disclosed in Japanese Patent Application Publication No. 2007-67236.